Speedometer



J. BERG E SPEEDOMETER May 22, 1928.

Filed May 16. 192 3 Sheets-Sheet 1 iii? m "m 2 v Q I May 22, 1928.

J. BERGE SPEEDOMETER Filed May 16.1921

3 Sheets-Sheet 5 Patented May 2 2, 1 928.

' ,"UNITEDASTATES PATENT OFFICE.

JosEPIi nnnen, or DAYTON, OHIO,ASSIGNOR To A C SPARK PLUG COMPANY, or

' FLIN '.I.,*MICHIGAN, A CORPORATION or MICHIGAN.

' SPEEDOMETER.

Application filed May 16,

The .present invention relates to speedometers such as are ordinarily used on motor vehicles. In such apparatus the indicating member is usually arranged to turn on a vertical or substantially vertical axis, whereas it is generally essential that the driving shaft enter the speedometer casing at an angle to the vertical, and it is common practice to employ a set of bevel or other gears as the connection between the driving shaft and the rotating member, from which the indicating member derives its torque. Due to inaccuracies'of cutting or adjustment or to wear consequent to difficulties of lubrication, the gears tend to become noisy, which is a serious objection, particularly in high grade cars. In accordance with one phase of the present invention, the gears are superseded by a flexible coupling, preferably a cable of special construction, which not only runs quietly atall times, but is also in; expensive to manufacture, easily installed, and capable of giving uniform service throughout the life of the instrument.

Another phase of the invention deals with a novel and highly desirable relation of the speed indicating member in respect to the magnet and rotor, in that the parts are so arranged as to secure adjustment without varying the gap between the magnet and the magnetic mass, one of which is rotatable. In the preferred construction shown, the magnet and the mass are assem bled in proper relation each to the other, and the indicating member is inserted more 'or less into the ma etic field to thereby establish the desired lntensity of drag.

Again, the invention is concerned with a particular mounting for the indicating member, whereby it is supported both from above and below, and whereby the various necessary adjustments are readily effected.

The invention also provides a more simple and inexpensive rotor or armature than has been available heretofore, so far as I am informed;

The invention is further concerned with various other relations of parts and with various details of construction hereinafter pointed out. I In'the drawings,

Fig. l is a perspective view, the casing and the magnet being omitted, and the speed indicating member, the rotor, and certain 1921. Serial No. 470,062.

other elements being broken away to more clearly show the construction; .Fig. 1 shows the construction of the flexible coupling or cable more clearly;

Fig. 2 is a central vertical section in the plane of the flexibie couplingand showing the parts assembled in the casing;

Fig. 3 is a plan view corresponding to Fig. 2, the casing being. shown in section;

Fig. 4 is a front elevation, parts being broken away, on a plane at the rear of the odometer; 4

Fig. 5 is a section on line 55 of Fig. 2;

Fig. 6 is a perspective view, parts being broken away, showing a modification wherein the magnet is arranged in a horizontal, or substantially horizontal, plane; and

Fig. 7 is a central vertical section corresponding thereto.

1 indicates the main element of the frame, preferably of aluminum, which conforms generally to the inner surface of the back 2 of a substantially cup-shaped casing 3,

hereinafter more fully described, said frame including a forwardly extending cross-wall 4 formin a bearing 5 having a vertical axis and also including a downwardly and rearwardly inclined extension 6 forming a hearing 7 for a main hollow drive shaft 8. Connection for driving the latter from a flexible shaft 9 is made preferably by means of a non-circular end portion 10 and socket 11 with which the shafts 8 and 9 are respectively provided. The casing 'for the flexible shaft appears at 12 and is preferably connected with the extension 6 in the manner set forth in my United States Patent No. 1,324,787, December 16, 1919. It will be understood that the driving connection 9-10 permits relative longitudinal movement of the parts. At its inner end the shaft 8 is enlarged and forms a worm 15 through which odometer mechanism is driven, as will be more fully explained later. Means such as a collar 16 pressed on the shaft 8 retains the latter in its bearing: Mounted in the bearing 5 is an upright hollow rotor shaft 20, preferably of soft iron or steel, on the upper end of which a rotor 21 is secured, preferably by press-fitting, said rotor preferably being spidershaped with the ends of the several arms or legs upturned at 22 so as to describe the surface of a cylinder in their travel. As

will-be seen from Fig. 3, the angular width of any given rotor arm is preferablyless than the angular distance between adjacent arms; and it is desirable also that an odd number of arms be used, so that an arm on one side of the rotor is substantially opposite the gap on the other side. Obviously, the rotor may be conveniently formed by stamping. It is desirable, in order .to save space, that the arms be offset downwardly from the,mid-portion of the rotor as shown.

.The shaft may be lubricated, if desired,

. by a saturated felt or wicking 23 arranged to contact with the casing and to be pressed thereby against the shaft.

For driving the rotor shaft 20 from the main shaft 8, a flexible coupling 25 is preferably provided, the same being preferably formed of a steel wire core 26 surrounded by wires of the cable together at the ends (see.

Fig. 1") and fitting them into metal tips 28, substantially square in cross-section, and thereafter indentin the walls of the tips into the formed en s of the cable by means of a suitable tool, as indicated at 29. The inner surfaces of the shafts 8 and 2Q are of "course shaped by broaching or otherwise, as

shown at 30, to receive and conform to the t1ps 28, a slight clearance being referably 1 provided. In assembling, the ca le is first inserted into the shaft 8, the upper end of the cable is next inserted into the bearing into said bearing 5, the shaft 20 is then inserted from above ceives the tip 28 and a collar or sleeve 31, which was initially threaded over the cable, is finally pressed upwardly onto the lower end of the shaft 20 to retain the latter in position.

It will be noted, as suggested heretofore,

- that the cable 25 is free to assume its natu- .regardless of the particular instrument or association of which it forms a part, and regardless of whether the axes are inclined to each other, offsetfrom .eaeh ,other, or

parallel.

Supported on the frame 1 in proper relation to the rotor 21 is a magnet 35 which, in the construction shown, is of the horse-Q shoe ty e with its axis substantial-1y per-- pendicu'ar or slightly inclined to the axis .1

t 20 and with? the upper .of the rotor sha end portions 36 of its legs parallel to... one another (see Fig. 4). "The-attachnent of the magnet to the frame may of course vary,

but this may be effected by slotting the.

frame, as best shown in Fig. 3, "and by the use of clips 37, Fig. 4, fastened to the frame by screws38. It will be evident tofthoseskilled in the art that the magnet may be shaped and =arranged otherwise than as shown, and that its axis may bear a relation to the rotor axis otherwise than the -perpendieular or nearly perpendicular relation specifically set forth, one such construction being shown in Figs. 6 aiSld 7 For purposesof menu actu're and adjustment, it is preferred to formthe speed indie cating unit readily attachable to and detach-- able from the frame, as will now be described :-Thisunit comprises, in its pre ferred form, a support having two later al arms 40 provided with guide surfaees'41 coacting with corresponding surfaces 42, Fig. 3, formed on the framel. Screws 43,

threaded into the arms 40 and passing through slots 44 in the frame, Fig. 1, to-.

gether with ascrew 45'threaded in the support and having its lower end bearing on the frame, or on a plate 46 itself inset into a slot formed in the frame, provide means for' adjusting the support in a direction parallel to the axis of the shaft 20, and for securing it in an iven position, of such adjustment, as wil e obvious. The support also comprises two forwardly extending arms 48 and 49, the latter being downwardly inclined and terminating in'a cup 50 wherein abearing jewel 51 is received. As.

-. shown, the cup projects into the hollow of the rotor shaft. The arm-48 is ierced and threaded torece'ive the screw 52 in the lower (in which process it re-' hollow end of 'which ajewel bearing 53 is referablysupported, and between the bear 1ngs'51 and. 53 is mounted the staff or pinion 54 of the light non-magnetic oscillatory in dicating or drag element 55, formed of a metal which isboth light and a good conductorof electricity. The particular metal is not a part of i the present invention, but

an alloy of substantial] 97% aluminum to in passing to the Iii rotor or magnetic mass also passes through the barrel. Therefore when the rotor is turned, the indicating element will be dragged along with a force corresponding to the speed of the rotor, being resisted by a hair spring in the usual way. For convenience in adjusting the tension of the hair spring, its outer end is attached to an arm 61, the inner end of which is split at 62, Fig. 3, and receives, by a spring fit, a cylindrical boss formed on the upper side of the arm 48, and a nut 63, which serves as a lock Znut for the screws 52, retains the arm 61 in position without interfering with the ready angular adjustment thereof by hand. In order to stiffen the indicating element, it is preferably offset downwardly and inwardly within the upper ends 22 of the rotor to form a substantially annular flange 55, bcst'shown in Fig. The spoke which connects the hub of the indicating element to the flange 55 appears at 55", and is preferably reinforced by stamping a rib therein.

The intensity of drag on the indicating element is determined by its adjustment longitudinally of the parallel legs of the magnet, being greatest when the upper ends of said legs are above the upper ends of the poles 22 of the rotor a distance substantially one-half the thickness of the metal of which the magnet is made.

In the modification shown in Figs. 6 and 7, the upright magnet 35 is replaced by an arcuate or C-shaped magnet 35 which has a substantially vertical axis and conforms rather closely to or surrounds the indicating element except at the front, where the numerals thereon may be read through the opening. ing the magnet in position, the frame. 1 may be provided with the shelf on shelves 6 1,

notched at 65 and bossed at 66 for the reception of the magnet and the clamping screws 67, respectively. Other things bein equal. the magnet thus arranged gives increased torque per unit of sectional area over what can be secured with the construction heretofore described, inasmuch as substantially no lines of force are permitted to shunt around the rotor, but on thecontrary practically all pass through its poles. By thus increasing the torque, a stronger coil spring may be .used, thus giving more nearly a dead beat instrument than in the other arrangement. Otherwise than the arrangement an(l'"construction of the magnet the parts shown in Fig. 6 are, or may be, the sameas those more specifically described in connection with Figs. .1 to 5, inclusive, and are designated by the same numerals.

It is, of course, desirable that the instrument register the total and usually also the trip mileage or distance, and for this purpose odometer mechanism, the moving parts of which are designated 7 0 as a whole, is

As a. convenient means for securprovided, said-mechanism being driven from the worm 15 through the medlum of the shafts 71 and 72 and associated gearing of for this purpose the odometer frame 73 is I formed separate from. the frame 1 and arranged for ready mounting thereon through the medium of the shoulders 74 and centering bosses 75 formed on the latter, and the SCILWS 76, Fig. 3. 3

The casing;- maybe of any suitable con.- struction, but it is preferred that it be of steel (to relieve the magnetic field of external influences) and of the cup-shaped type.

The particular construction shown, together with-the mounting thereof, is made the sub jcct of my companion application S. N. 481,685, filed June 30, 1921.

As a means for lubricating the worm gearing on the shaft 71, asavell as the shaft 8, a pad of saturated felt or the like, encircling the shaft 8 between the worm 15 and the casing and disposed between the casing and the shaft 71, may be employed, and for additional lubricationof the shaft 8 it may be advisable to employ a packing 81 of similar material insertcdin a hole in the frame. A felt washer 82 or the like is used to seal the joint between the frame and the casing.v

What I claim is:

1. 1 magnetic speedometer comprising a stationary magnet, a rotor, a. drag-element including a substantially cylindrical'fiange interposedbctween the rotor and both poles of the magnet, said rotor being of spidershape with the ends of the arms substantially parallel to the axis about which the rotor turns, so that said ends describe a substantially cylindrical surface ust within said flange.

loo

lit)

2. A magnetic speedometer comprising a stationary magnet, a spider-shaped rotorrotatablc in.the field of said magnet and including arms the ends of which describe a common surface of revolution during the rotation of the rotor, an angularly movable non-magnetic i drag-element including a flange surrounding the ends of said arms and interposed between the same and the poles of said magnet.

3. In a magnetic speedometer, astationary magnet, a non-magnetic speed indicating member and an armature rotatable about a common substantially vertical axis, said' i dially disposed arm s having their outer endsrl'lp-turned withingand slightly spaced a i n- {ii In a.

;- from thcaspefed indicatingmember, said inz 1 and an] armatiire'lassociated therewith so '10 ment' of the drag-element aboutthe same' that rotation off the -'.armaturc causes moveaxis', said armature being of spider-shape and comprlslng an odd number of arms, said element being interposed between said armature and both poles of said magnet. '5. A magnetic-speedometer comprising a casing having a substantially horizontal axis, a... rotor rotatable therein about a sub st-antially vertical axis, a fixed permanent magnet of the horse-shoe typearranged in a'plane at. a large angle to thmhorizontal and having the more intense part of its field cut by said rotor in its movement, and

a drag-element interposed between the poles of the magnet and the rotor and mounted for angular movement about the axis of the rotor tin such manner as to be deflected durin the rotation of said rotor;

1 6. magnetic speedometer comprising an armature rotatable about a substantially ver tical axis, a speed indicating member surrounding the armature and being rotatable about the'same axis, a horse-shoe ma et arranged in a plane at a large angle to the horizontal and embracing said member, the limbs of'the magnet being parallel to each other and-to said axis in the vicinity of said member, and means for adjusting said member along said limbs.

7. In a magnetic speedometer,'a frame :having a pair of spaced substantially ver- I adjusting the support a tical guides. a support including a pair, of arms slidable-along said lguides,,means for o g said guides, said support also having rigld therewith a second pair of arms, and a speed indicating member carried between the ends of said sec-- ond pair of arms and movable angularly about a'substantially vertical axis. I

8. In a magnetic speedometer, a frame having a substantially vertical guide, a support slidable along said guide, said support including a pair of arms integral with each other the outer ends of which are in verti cal alignment, and a speed indicating member having a spindle carried by said outer ends of the arms.

9. In a magnetic speedometer, a frame having a substantially vertical guide, a. support slidable along said guide, said support including a pair of arms integral with each other the outer ends of which are in vertical'alignmerit, a speed indicating member having a spindle carried by said outer ends of the arms, a hair spring carried by said support and opposing angular movement oi the speed indicating member in one direction, and an arm adjustable about the axis of the spindle for varying the tension in said spring. 10. Ina 'magnetic-speedometer, a fixed magnet, a rotor rotatable in the field thereof, a frame by which the magnet and rotor ,are supported, and a drag-element assembly bodily adjustable in a direction parallel to 'the axis of the rotor and embodying a thin non-magnetic metal speed indicating mcin-i ber interposed between said rotor and the poles of the magnet, a staff therefor, means for supporting the staff at both its upper and lower ends, and a. spring resisting angular movement of said'member.

11. In: an instrument of the class described, two members, onea permanent magnet of the horseshoetype having substantially parallel connected limbs and the other a magnetic mass, one of said members being rotatable about an axis substantially equally distant from the poles of said magnet, the mass being positioned in the space between the extreme outer ends of the limbs and the connection between said limbs, and a nonmagnetic speed indicating element interposed between-the ends of said limbs and said mass to be deflected bvtorque derived from rclature.

JOSEPH BERGE. 

